Soluble Unit Dose of Laundry Detergent

Abstract

A soluble unit dose of laundry detergent which comprises: a) a thin walled hard capsule, having a wall thickness between 0.07 and 0.3 mm and, c) within the thin walled hard capsule a detergent composition comprising at least 1 g of surfactant, which makes up at least 45% wt of the detergent composition. wherein the solubility of the capsule and the detergent composition is such that it will reach a level of 90% of eventually dissolved electrolytes in stirred demineralised water at 25° C. in less than 35 seconds. By choice of a capsule with this wall thickness the solubility is ensured while pressure caking of the contents is resisted to minimise overall dissolution time.

1 . A soluble unit dose of laundry detergent which comprises:
 a) a thin walled hard capsule, having a wall thickness between 0.07 and 0.3 mm and,   b) within the thin walled hard capsule a detergent composition comprising at least 1 g of surfactant, which makes up at least 45% wt of the detergent composition.   
       wherein the solubility of the capsule and the detergent composition is such that it will reach a level of 90% of eventually dissolved electrolytes in stirred demineralised water at 25° C. in less than 350 seconds. 
     
     
         2 . A soluble unit dose according to  claim 1  wherein the hard capsule wall thickness is between 0.08 and 0.2 mm. 
     
     
         3 . A soluble unit dose according to  claim 1  or  claim 2  which floats when added to water. 
     
     
         4 . A soluble unit dose according to any preceding claim wherein the detergent composition has an unconfined compression test value, as defined herein, of greater than 1000 g at 35° C. 
     
     
         5 . A soluble unit dose according to any preceding claim wherein the capsule is formed from hydroxy-propylmethylcellulose. 
     
     
         6 . A soluble unit dose according to any preceding claim wherein the contents of the capsule are of particulate form. 
     
     
         7 . A soluble unit dose according to  claim 6  wherein the particles have an average diameter of 0.1 to 2 mm. 
     
     
         8 . A soluble unit dose according to any one of the preceding claims wherein the surfactant is a calcium tolerant surfactant as defined herein. 
     
     
         9 . A soluble unit dose in which the headspace in the capsule is less than 20%, preferably less than 10%. 
     
     
         10 . A soluble unit dose in which the bulk density of the detergent composition is greater than 500, preferably greater than 700 even greater than 900 g/l. 
     
     
         11 . A soluble unit dose in which the weight of the capsule makes up less than 20% of the total weight of the unit dose, preferably less than 15%. 
     
     
         12 . A soluble unit dose according to any preceding claim wherein the capsule is opaque. 
     
     
         13 . A soluble unit dose according to any preceding claim wherein the capsule is coloured. 
     
     
         14 . A soluble unit dose according to  claim 12  or  claim 13  wherein the outside surface of the capsule is printed. 
     
     
         15 . A soluble unit dose according to any preceding claim wherein the capsule provides a moisture resistant barrier. 
     
     
         16 . A soluble unit dose according to  claim 13  wherein the capsule is sealed with a band and provides an effective barrier to the transmission of water vapour. 
     
     
         17 . A soluble unit dose according to any preceding claim wherein a part of the detergent composition is contained in a smaller capsule within the main capsule, the smaller capsule preferably being sealed with a band. 
     
     
         18 . A soluble unit dose according to  claim 17  wherein the smaller capsule contains bleach. 
     
     
         19 . A soluble unit dose according to  claim 18  wherein the smaller capsule is coated. 
     
     
         20 . A method for laundering garments which comprises the step of introducing into a washing machine at least two thin walled hard capsules which each contain a detergent composition comprising more than 45 wt % surfactant, the weight of surfactant in each capsule being at least 1 g. 
     
     
         21 . The method according to  claim 18  in which the filled capsules initially float on water and are introduced to the washing machine via a dispensing drawer from which they are flushed by a flow of water. 
     
     
         22 . A method according to  claim 18  or  19  wherein the T90 value for the capsules and their contents is less than 350 s. 
     
     
         23 . A method according to  claim 20  wherein the T90 value is less than 250 s. 
     
     
         24 . A method according to  claim 20  wherein the T90 value is less than 180 s.